There is a large and increasing demand for reproductions of original works of art that accurately reflect both the true color and texture of the original.
U.S. Pat. No. 5,667,747 describes a process and apparatus for molding a thin sheet of thermoplastic material into an accurate three-dimensional relief image that mimics the brushstrokes of the original art. While this reproduction is a great improvement over two-dimensional photograph-like reproductions, the surface of the reproduction has a smooth plastic-like feel and the degree of gloss or shine tends to be constant over the entire surface. In original paintings, some areas naturally tend to be glossier than others due to, for example, the quality, age and amount of oil in the pigment used. Particularly in works of art which combine mixed media, there are areas which have different degrees of glossiness and/or texture.
With both original works of art and reproductions, protective coatings are often used to prevent damage to the image due to wear and tear, ultraviolet radiation, etc. When dealing with reproductions on a material such as PVC, the coating should have certain characteristics. The composition must be one that adheres well to PVC both in the wet and dry states. It should not interact with the pigments of the image or with the PVC material itself and the coating should not discolor or obscure the image, rather it should provide enhanced wearability and abrasion resistance.
Various types of coatings have been used to protect original artistic images. These include, for example, varnishes, waxes and synthetic resins. Certain finishes, such as acrylic gel containing sand, are sometimes used by artists to create special effects. While these coatings may be suitable for certain types of original artwork, they are not very effective as coatings on artistic reproduction on thermoplastic material. Acrylic gel, for example, does not adhere well to PVC and the finish easily peels off.
It is known to produce polyurethane coatings on PVC. U.S. Pat. Nos. 3,265,805, 4,017,493 and 4,045,600 describe processes for coating PVC using one component or two component polyurethane systems. However, the use of solvent containing coating agents presents problems both in terms of the health of the worker and in terms of reactivity with the substrate to be coated. U.S. Pat. No. 4,876,302, addresses this problem by disclosing aqueous coating compositions suitable for use as coating and finishing agents for PVC surfaces.
A further problem associated with many of the available coatings for PVC is that they provide a smooth homogenous cover while the surface of an original painting often has a degree of texture. This texture is due to both the composition of the paint used and the inherent texture departed by the canvas on which the image is painted. Thus, there remains an unmet need for a coating composition for artistic images, particularly reproductions on thermoplastic materials, that can impart realistic texture to the surface.
Synthetic resins incorporating glass beads are known. For example, JP11050378 discloses water-proofed cloth which is coated with polyurethane containing glass beads. The cloth provides superior waterproofness, luminescence and re-reflecting properties. U.S. Pat. No. 5,981,033 discloses pavement marking tape in which glass beads which reflect incident light are held in a polyurethane binder. JP06010319 discloses a road mark material which comprises glass beads having a diameter of about 50 to 3000 microns in a reactive oligomer. The coating is designed to have good abrasion resistance. However, while synthetic resin compositions including glass beads are known, their use as a coating for imparting surface texture to an artistic reproduction is novel.
The present invention addresses the problems of the prior art by providing a coating composition and a method of coating an artistic reproduction that results in a surprisingly realistic texture on the surface of an artistic reproduction.